CVE-2026-103262CWE-409

CVE-2026-103262

High · published October 1, 2026

CVSS v3.1
7.5
EPSS
1%
Percentile
43.7
In the wild
Unconfirmed
What it is

Tornado versions before 6.5.9 contain an unbounded memory accumulation vulnerability in CurlAsyncHTTPClient that allows remote attackers to cause denial of service by sending a compressed response. Attackers can send a gzip-encoded decompression bomb that accumulates in memory without size limits, causing the application process to be killed by out-of-memory conditions.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
8.7 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
EPSS
0.00525 · 43.7th percentile
Weakness
CWE-409 · Improper Handling of Highly Compressed Data (Data Amplification)
Published
2026-10-01T15:17Z
References (4)
https://github.com/tornadoweb/tornado/commit/e412435febba4569c552c5c9054f1bf92bd171a9 · [email protected]https://github.com/tornadoweb/tornado/security/advisories/GHSA-chx6-46f5-w4vp · [email protected]https://www.vulncheck.com/advisories/tornado-before-6.5.9-denial-of-service-via-curlasynchttpclient · [email protected]https://github.com/tornadoweb/tornado/security/advisories/GHSA-chx6-46f5-w4vp · 134c704f-9b21-4f2e-91b3-4a467353bcc0
EPSS history
Timeline
  • 03 OCT 03:41Z
    EPSS moved — → 1%
    epss
  • 01 OCT 10:42Z
    Tornado before 6.5.9 Denial of Service via CurlAsyncHTTPClient
    cvelistv5